Barrel link in Vic woman's murder

A Melbourne grandmother's body was found in a barrel almost identical to one found in her husband's backyard, an inquest has heard.

Lucia Amenta's remains were found in a barrel the same size and colour as one found in her husband Paolo's backyard, but it bore different date stamps, Detective Senior Constable Nathan Toey told an inquest into her death.

The court heard youngest son John Amenta had told a friend in a conversation taped by police the backyard find was a bad look.

"My old man's got 10 barrels at home. It looks bad because they found her in a barrel and he's got barrels. It doesn't make us look good at all," he said.

In a separate phone conversation, John threatens a woman to get her act together or "I swear on my mum you're going to die too".

In another conversation read to the court he told another friend police believed he and his father were behind his mother's death.

Mrs Amenta disappeared from her Fawkner home in January 2008 after she had cooked lunch to take to John.

Her husband Paolo said he went to buy bread and when he returned she was gone.

Paolo said he believed she had gone to see a friend but he didn't know who.

Her body was found in a barrel fished out of a lake at a Campbellfield reserve in October 2009.

John and Paolo foreshadowed they would assist the inquiry and testify but apply for immunity certificates because their barrister Jason Buckland told the court he was concerned about a "potential knock-on effect" to "other proceedings that have not been instigated yet".

Det Sen Const Toey said Mrs Amenta dominated her husband, who she would nag and hit, but it would end in laughing.

The inquest heard she was very close to John, who had a criminal history involving drugs, assault and theft, and had an extravagant lifestyle including a Ferrari with the number plates "Bail".

No one has been charged over the death and police this month posted a $100,000 reward to help solve the case.